JP2019215364A - Water-bottom observation system - Google Patents

Abstract

To provide a water-bottom observation system that can highly accurately generate water-bottom surface data even when photographing a water-bottom area a solar light beam does not reach.SOLUTION: A water-bottom observation system 1 comprises: a submarine 2; an underwater video camera 3 that is mounted to the submarine; a laser range-finding device 4 that measures a distance from a laser beam reflected at a seabed face to a sea bottom face; a GNSS/gyro device 5 that detects a three-dimensional location and posture of the underwater video camera 3 and the laser range-finding device 4; and a video recorder that synchronously records photographed photographing image data and location data on the underwater video camera 3 and posture data thereon. The water-bottom observation system is configured so as to be able to, as to an overlapping range of a plurality of photographing images, generate DSM data having a geographic coordinate given by image processing based on respective location data and posture data thereon, and complementary-purpose DSM data capable of generating an orthographic projection photomap, and complementing the DSM data on the basis of measured water depth data and the posture data.SELECTED DRAWING: Figure 1

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water bottom observation system that acquires water bottom image information of a sea or a lake, processes the image, and observes the water bottom.

  Japanese Patent Laying-Open No. 2003-4845 (Patent Literature 1) discloses an observation method using an acoustic sounding device that supports the water surface so that it can travel and move (see FIG. 1 of Patent Literature 1). Although it is possible to obtain map information of a wide range of seafloor topography by water depth observation, it is limited to water depth observation in extremely shallow areas, and it is not possible to observe deep water bottom.

  Further, Japanese Patent No. 4173027 (Patent Document 2) discloses an observation method using a video camera supported tow so as to be able to move underwater (see FIG. 1 of Patent Document 2). It is possible to observe images over a wide range.

JP-A-2003-4845 Japanese Patent No. 4173027

  Here, the underwater image obtained by the video camera can grasp the optical properties by dynamic observation in the water, but it is transient image information and does not have geographic coordinates, so it relates to the aspect of the water bottom There was a problem that it could not be the basis of quantitative analysis covering the entire optical properties.

  Furthermore, in Japanese Patent Application Laid-Open No. H11-157, the water bottom image is configured to be captured by a video camera. Therefore, when capturing the bottom of the water at dawn / dusk, or when the depth of the water is too deep to reach the sunlight. When imaging a water bottom area, when imaging a water bottom area where water quality is polluted, or when a water bottom area to be imaged is shaded, it is not possible to accurately create water bottom surface data. was there.

  Therefore, the present invention captures an image of a water bottom area where the water quality is polluted when capturing an image of a water bottom area at the time of sunshine or at dawn / dusk, or when imaging a water bottom area where the water depth is deep and the sunlight does not reach. In this case, an object of the present invention is to provide a water bottom observation system capable of accurately generating water bottom surface data together with a geographical coordinate position even when a water bottom area to be imaged is shaded.

Such objects of the present invention are:
A submersible vehicle that can move underwater,
A plurality of underwater cameras that continuously detect visible light mounted on the submersible,
A laser ranging device that emits a laser beam, receives the laser beam reflected by the sea bottom, and can continuously measure the distance to the sea bottom in synchronization with the plurality of underwater cameras,
An attitude sensor that detects the attitude of the plurality of underwater cameras and the laser ranging device,
A GNSS sensor that detects a shooting position of the plurality of underwater cameras and a measurement position of the laser ranging device;
Synchronously recording photographed image data photographed by the plurality of underwater cameras, posture data of the plurality of underwater cameras detected by the posture sensor, and photographing position data of the plurality of underwater cameras detected by the GNSS sensor. Recording means,
An image processing means for processing a recorded image of the recording means,
The image processing means, for an overlapping range of a plurality of captured images captured by the underwater camera, DSM data to which geographic coordinates are given by image processing based on respective attitude data and captured position data; The DSM data is complemented based on water depth data indicating the distance to the bottom of the water measured by the laser ranging device and attitude data of the laser ranging device detected by the attitude sensor. Complementary DSM data can be created,
The laser ranging device includes a storage unit that stores an emission time and an intensity of the emitted laser beam, a photosensor that detects a detection time of the laser beam reflected by the sea bottom, and a photo sensor that is reflected by the sea bottom. The present invention is achieved by a water bottom observation system having a light receiving sensor having an area sensor for detecting the intensity of the laser beam.

  In this specification, DSM is an abbreviation for Digital Surface Model, and refers to a numerical surface model.

  According to the present invention, in the underwater observation system, since a plurality of underwater cameras that detect visible light are mounted on the submersible vehicle, the underwater images are captured by the plurality of underwater cameras, and the state of the underwater is visually observed. It can be shown easily.

  Further, according to the present invention, in addition to a plurality of underwater cameras that detect visible light, the water bottom observation system includes a laser distance measuring device that can measure the distance to the water bottom. Due to lack of sunlight and insufficient brightness, multiple underwater cameras that detect visible light cannot accurately create underwater surface data. If some of the underwater cameras are missing or the water quality is polluted, it may not be possible to accurately create water bottom surface data with multiple underwater cameras that detect visible light. If some of the bottom surface data obtained by the camera is missing, it will be shaded when capturing the bottom with multiple underwater cameras that detect visible light. If some of the underwater surface data obtained by multiple underwater cameras are missing, the sun's shadows, dawn / dusk, or very high contrast may cause a lack of brightness. When a part of the underwater surface data obtained by multiple underwater cameras is missing due to the formation of a part where sufficient exposure is not obtained, and the underwater surface data obtained by multiple underwater cameras is missing (image matching processing) Is difficult to perform, and even if part of the bottom surface data is missing, the distance to the water depth is measured with a laser ranging device, and the bottom surface data obtained by multiple underwater cameras that detect visible light is measured. It becomes possible to supplement the defect.

  In a preferred embodiment of the present invention, the laser distance measuring device includes a diffusing member for diffusing the laser beam and irradiating the sea bottom with an n × n matrix.

  In a preferred embodiment of the present invention, the underwater camera is a video camera whose shutter can be controlled, and the plurality of video cameras are arranged on the left and right.

  According to this preferred embodiment of the present invention, since the video cameras are arranged on the left and right sides, it is possible to secure an 80% overlapping range for the water bottom image and efficiently shoot the water bottom image. Even if there is a sudden change in viewpoint due to, a clear water bottom image can be taken, so that the accuracy of image processing can be improved.

  In a preferred embodiment of the present invention, the attitude sensor and the GNSS sensor are configured by a GNSS / gyro device.

  ADVANTAGE OF THE INVENTION According to this invention, when imaging a water bottom area | region at the time of the dawn / dusk at the dawn of sunlight, or when imaging the water bottom area where the water depth is deep and sunshine does not reach, the water bottom area where water quality is polluted is imaged. In this case, it is possible to provide a water bottom observation system capable of accurately generating water bottom surface data together with the geographic coordinate position even when the water bottom region to be imaged is shaded.

FIG. 1 is a functional configuration diagram of a water bottom observation system according to a preferred embodiment of the present invention. FIG. 2 is a block diagram showing components of the underwater observation system according to the preferred embodiment of the present invention shown in FIG. FIG. 3 is a schematic perspective view of a laser beam emitting unit of the laser distance measuring device. FIG. 4 is a schematic perspective view of a laser beam receiving unit of the laser distance measuring device. FIG. 5 is a schematic vertical sectional view of the light receiving sensor. FIG. 6 is a block diagram of a control system and a detection system of the laser distance measuring device. FIG. 7 is a flowchart showing a process of observing the water bottom by the water bottom observation system according to the preferred embodiment of the present invention shown in FIGS. 1 to 6.

  FIG. 1 is a functional configuration diagram of a water bottom observation system according to a preferred embodiment of the present invention. FIG. 2 is a block diagram showing components of the water bottom observation system according to the preferred embodiment of the present invention shown in FIG. It is.

  As shown in FIGS. 1 and 2, a water bottom observation system 1 according to a preferred embodiment of the present invention includes a submersible vehicle 2 movable in water, and a pair of underwater video cameras 3, 3 mounted on the submersible vehicle 2. (Only one is shown in FIG. 1), a laser ranging device 4 mounted on the submersible vehicle 2, a shooting position of the pair of underwater video cameras 3, 3, and a ranging of the laser ranging device 4. GNSS / gyro device 5 that detects the position and detects the attitude of the pair of underwater video cameras 3 and 3 during shooting and the attitude of the laser ranging device 4 during ranging, and shooting with the pair of underwater video cameras 3 and 3 Data of the detected underwater image, photographing position data of the pair of underwater video cameras 3, 3 and photographing position data of the pair of underwater video cameras 3, 3 when photographing the underwater image detected by the GNSS / gyro device 5. Video recorders 7 and 7 that record the data in synchronization with each other and image processing of the water bottom images in real time on the submersible vehicle 2 based on the water bottom image data, the photographing position data and the attitude data recorded on the video recorders 7 and 7. Alternatively, a personal computer 9 having an image processing unit 8 for performing image processing of a water bottom image after the photographing operation is completed is provided.

  As each video camera 3, a video camera which is housed in a housing and has an electronically controllable high-speed shutter and is capable of underwater photography is used. Each of the video cameras 3 is capable of capturing 80% of the underwater image, and is capable of recording a clear image with a high-speed shutter even when shaken by waves.

  Although only one of them is shown in FIG. 1, a pair of underwater video cameras 3 and 3 are disposed on both left and right sides of the submersible vehicle 2.

  The GNSS / gyro device 5 is configured to detect a three-dimensional photographing position of the pair of underwater video cameras 3 and 3 and a three-dimensional distance measuring position of the laser distance measuring device 4 so that a high-precision DGNSS can be applied. , The GNSS / gyro device 5 further includes the attitude data of the pair of underwater video cameras 3 and 3 in the optical axis direction and the attitude of the laser distance measuring device 4 at the time of distance measurement, that is, the laser beam from the laser distance measuring device 4. It is configured to detect the emission direction.

  The video recorders 7, 7 are water bottom images taken by the video cameras 3, 3, shooting position data of the video cameras 3, 3 detected by the GNSS / gyro device 5, and attitude data of the video cameras 3, 3. Is synchronously recorded on a recording medium, and is input to an image processing unit 8 of a personal computer 9 mounted on the submersible vehicle 2. Alternatively, the water bottom image photographed by each video camera 3, 3 is synchronously recorded with the photographing position data of each video camera 3, 3 and the posture data of each video camera 3, 3 detected by the GNSS / gyro device 5. It is also possible to configure so that the portable media or these data can be input by radio transmission to an image processing unit (not shown) of a personal computer (not shown) located on the ground.

  The image processing unit 8 includes video data of the water bottom generated by the pair of video cameras 3, 3, the attitude data of the pair of video cameras 3, 3 detected by the GNSS / gyro device 5, and the pair of video cameras 3, 3. Is input, and the image processing unit 8 of the personal computer creates DSM data, which is a numerical ground model represented on geographical coordinates, based on these data by stereo matching. It is configured.

  As shown in FIG. 2, the water bottom observation system 1 further includes video editors 12, 12, a synchronization signal generator 14 for generating a synchronization signal, a DSM data generator 15 for generating DSM data, and a DSM data generator. Is provided with an orthophotograph generation unit 16 for generating an orthophoto based on.

  FIG. 3 is a schematic perspective view of a laser beam emitting unit of the laser distance measuring device 4.

  As shown in FIG. 3, the laser distance measuring device 4 includes an LED laser light source 21 that emits a laser beam 20 in a pulse shape, and the laser beam 20 emitted from the LED laser light source 21 enters a collimator lens 22. And converted into a parallel beam. The laser beam 20 converted into a parallel beam by the collimator lens 22 is incident on the diffusion member 23, and the laser beam 20 is divided into a number of laser beams 25 by the diffusion member 23, and is divided into an n × n matrix. For example, the sea bottom is irradiated in a 128 × 128 matrix.

  As the diffusion member 23, for example, a diffusion member used in “3D Flash Lidar” (registered trademark) manufactured and sold by Advanced Scientific Concepts, Inc. is preferably used.

  FIG. 4 is a schematic perspective view of a laser beam receiving unit of the laser distance measuring device 4.

  As shown in FIG. 4, the laser beam 45 divided by the diffusion member 23 and reflected by the sea bottom is condensed by the condenser lens 26 and is photoelectrically detected by the light receiving sensor 27.

  FIG. 5 is a schematic longitudinal sectional view of the light receiving sensor 27. As shown in FIG. 5, the laser beam 20 emitted from the LED laser light source 21 is reflected by the sea bottom to detect a laser beam 45 generated. And a CCD sensor 29 for detecting the intensity of the laser beam 45 reflected by the sea bottom.

  FIG. 6 is a block diagram of a control system and a detection system of the laser distance measuring device 4.

  As shown in FIG. 6, the laser distance measuring device 4 calculates the time when the laser beam 20 is emitted from the laser light source 21 in a pulsed manner and the laser beam 45 generated by the laser beam 20 being reflected by the sea bottom. A first memory area 30A for storing the time received by the photosensor 28, and a second memory for storing the intensity of the laser beam 20 emitted from the laser light source 21 and the intensity of the laser beam 45 detected by the CCD sensor 29. It has a RAM 30 having an area 30B.

  Further, in the laser distance measuring device 4, the photo sensor 28 receives the time when the laser beam 20 was emitted from the laser light source 21 stored in the first memory area 30A of the RAM 30 and the laser beam 45 reflected by the sea bottom. A controller 31 is provided for calculating the distance to the sea bottom based on the time, the intensity of the laser beam 20 emitted from the laser light source 21, and the intensity of the laser beam 45 detected by the CCD sensor 29.

  In addition, as shown in FIG. 6, the laser distance measuring device 4 includes a laser data processing unit 10 that processes data obtained by irradiation with the laser beam 20.

  When the laser beam 20 is split by the diffusing member 23 and irradiates the sea bottom in the form of an nxn matrix, the laser beam 25 reflected by the elements of the nxn matrix is converted into a photo sensor 28 and a CCD sensor. By performing the photoelectric detection by 29, the distance between the element and the laser light source 21 can be accurately calculated. Therefore, the distance between all the elements of the n × n matrix and the laser light source 21 can be accurately calculated. Becomes possible.

  FIG. 7 is a flowchart showing a process of observing the sea bottom by the water bottom observation system 1 according to the preferred embodiment of the present invention shown in FIGS.

  When a start signal is input to the personal computer 9 by the operator, a drive signal is output from the personal computer 9 to the synchronizing signal generating device 14, and the synchronizing signal generating device 14 outputs a pair of video cameras 3 and 3 and a laser measurement signal. A synchronization signal is output to the distance device 4, the GNSS / gyro device 5, and the conversion software 35. At this time, the personal computer 9 stores the time at which the laser beam 20 was emitted from the laser light source 21 in the first memory area 30A in the RAM 30 of the laser distance measuring device 4, and the laser beam emitted from the laser light source 21 The intensity of 20 is stored in the second memory area 30B in the RAM 30 of the laser distance measuring device 7.

  Upon receiving the synchronization signal, the pair of video cameras 3, 3 starts shooting, and a color image of the shooting areas 32, 32 on the sea floor is shot.

  On the other hand, the laser distance measuring device 4 emits the laser beam 20 in a pulse form from the laser light source 21, converts the laser beam 20 into a parallel beam by the collimator lens 22, and makes the parallel beam enter the diffusion member 23. By passing through the diffusion member 23, the laser beam 20 is divided into a number of laser beams 25, an n × n laser beam 25, for example, a 128 × 128 laser beam 25. Irradiation is performed on the overlapping photographing region 33 where the photographing regions 32 on the sea bottom overlap, and an n × n matrix-shaped irradiation part 33A is formed in the overlapping photographing region 33.

  The laser beam 45 reflected by each of the n × n matrix-shaped irradiation units 33A on the sea bottom is condensed by the condenser lens 26 and is photoelectrically detected by the light receiving sensor 27.

  As described above, the light receiving sensor 27 includes the photo sensor 28 that detects the detection time of the laser beam 25 reflected by the sea bottom and the CCD sensor 29 that detects the intensity of the laser beam 25 reflected by the sea bottom. ing.

  When the photo sensor 28 detects the laser beam 45 reflected by each of the n × n matrix-shaped irradiation units 33A on the sea bottom, the photo sensor 28 detects the time when the laser beam 45 is detected in the first memory area 30A in the RAM 30. To be stored. Here, the first memory area 30A is divided into an n × n matrix memory area corresponding to the n × n matrix irradiation section 33A, and the photo sensor 28 The detection time of the laser beam 45 reflected by each of the matrix-shaped irradiation units 33A is stored in the corresponding matrix-shaped memory area in the first memory area 30A.

  On the other hand, the CCD sensor 29 detects the intensity of the laser beam 45 reflected by each of the n × n matrix-shaped irradiation units 33A on the sea bottom, and reflects the intensity by each of the n × n matrix-shaped irradiation units 33A on the sea bottom. The intensity of the obtained laser beam 45 is stored in the corresponding matrix memory area in the second memory area 30B.

  Next, the controller 31 accesses the RAM 30 to generate the laser beam 45 by the photo sensor 28 and the time when the laser beam 20 is emitted from the laser light source 21 stored in each of the matrix memory areas in the first memory area 30A. The detected time, and the intensity of the laser beam 20 emitted from the laser light source 42 and the intensity of the laser beam 45 detected by the CCD sensor 29 stored in each of the matrix-shaped memory regions in the second memory region 30B. Based on this, the water depth data of each of the n × n matrix-shaped irradiation units 33A on the sea bottom is calculated.

  In response to the synchronization signal, the GNSS / gyro device 5 generates attitude data and position data of the pair of video cameras 3 and 3, activates the conversion software 35, and converts the converted attitude data and the converted position data. Let it be calculated.

  In response to the synchronizing signal, image data corresponding to the image of the sea floor taken by the pair of video cameras 3 and 3 is output to the video recorders 7 and 7. Is generated. Next, the focal length and lens distortion are separately corrected using the observed camera parameters, and a corrected left and right serial number image (pair image every 1/30 second) is generated.

  Here, the camera parameters are observed by photographing a target separately set in an aquarium with the underwater video camera 3 and calculating the focal length and lens distortion using a photogrammetry formula.

  Next, for the corrected left and right serial number images, for example, template matching is executed to calculate the horizontal parallax.

  The lateral parallax calculated in this manner, the converted position data and the converted attitude data of the pair of video cameras 3 and 3 in which the position data and the attitude data measured by the GNSS / gyro device 5 are converted by the conversion software 35, and the lens The altitude value is calculated using the focal length of the first and the second depth data.

  Next, the corrected position data and the corrected attitude data of the video cameras 3 and 3 are used for the corrected serial number image (N-1) having the time difference between the left image and the right image among the corrected left and right serial number images. Then, geometric correction is performed on the same coordinates as the corrected serial number image N, and a geometrically corrected serial number image (N-1) is created.

  For example, template matching is performed on the geometrically corrected serial number image (N-1) and the corrected serial number image N thus obtained, and the vertical parallax is calculated.

  Next, the vertical parallax calculated in this manner, the converted position data and the converted attitude data of the pair of video cameras 3 and 3 in which the position data and the attitude data measured by the GNSS / gyro device 5 are converted by the conversion software 35, and , An altitude value is calculated using the focal length of the lens, and second water depth data is calculated.

  On the other hand, third depth data is calculated using the distance data generated by the laser distance measuring device 4, the position data and the attitude data of the laser distance measuring device 4, and the focal length of the lens.

  When the first depth data, the second depth data, and the third depth data are calculated in this way, the DSM data creation unit 15 creates DSM data.

  That is, the first depth data and the second depth data calculated based on the image data captured by the pair of underwater video cameras 3 and 3 are mainly used, and are generated by the laser ranging device 4 as complementary data. DSM data is created by interpolation / extrapolation calculation using the third water depth data calculated based on the obtained distance data.

  The DSM data created by the DSM data creation unit 15 is orthographically transformed by the orthoimage creation software 40 using the lens distortion corrected serial number image using the focal length of the lens, converted position data, and converted attitude data. Projected to create orthophotos in water.

  Here, the third water depth data generated by the laser distance measuring device 4 is, for example, the water depth data of an n × n matrix-shaped area 33A. Even if a matrix-shaped area 33A is generated and the respective depth data is obtained, the size of each area 33A is much larger than the pixels of the image taken by the pair of underwater video cameras 3, 3, so The accuracy is lower than the measurement accuracy based on the images taken by the video cameras 3 and 3. Therefore, in the present embodiment, the third depth of the matrix-shaped region 33 </ b> A generated by the laser Based on the data, complementary DSM data for complementing DSM data generated by images captured by the pair of underwater video cameras 3 and 3 is generated. It is configured.

  Thus, the DSM data of the seabed area to be photographed is generated by the DSM data generated based on the images photographed by the pair of underwater video cameras 3 and 3 and the complementary DSM data generated by the laser distance measuring device 4. You. In the present embodiment, the water bottom area can be visually observed even in the deep sea area by the pair of underwater video cameras 3 and 3. However, in the deep water region where the water depth is extremely deep, the sun rays do not reach, and it is often difficult to generate a clear water bottom image by the pair of underwater video cameras 3 and 3. In addition, since the complementary DSM data is generated by the laser distance measuring device 4, depending on the pair of underwater video cameras 3, 3, it is difficult to generate a clear water bottom image even in a deep sea region where the water depth is extremely deep. It is possible to determine the depth of the water bottom, measure the water bottom area and observe the water bottom as desired.

  Here, the supplementary DSM data generated by the laser distance measuring device 4 is not applied to the seabed area where the DSM data correctly generated from the images captured by the pair of underwater video cameras 3 and 3 exists.

  On the other hand, the corrected serial number image is superimposed and projected on the DSM data.

  Next, the orthographic photograph drawing creating unit 16 activates the ortho image creating software 40, and converts the obtained image using the converted position data and converted posture data generated by the converting software 40, Orthogonal projection is performed to create orthographic photographic image data.

  The observation is performed by moving the submersible 2 along the observation plan line, taking an image of the water bottom with the pair of underwater video cameras 3 and 3 as described above, and measuring the distance to the water bottom with the laser distance measuring device 4. At the same time, the GNSS / gyro device 5 detects the viewpoint position and the optical axis direction, which are the shooting conditions of the pair of underwater video cameras 3, 3, and the video recorders 7, 7 record the two in synchronization.

  After the observation is completed, the orthographic projection image data is input to the image processing unit 8 of the personal computer 9 mounted on the submersible vehicle 2 or a personal computer (FIG. (Not shown) and an orthographic image processing is executed.

  This image processing output can show the coral reefs and shallows in shallow waters in a shallow water area in a shallow water depth, so that the conditions of the coral reefs and shallows in the shallow waters can be visually understood easily. Therefore, according to the present embodiment, the underwater environment of coral reefs and shallows in shallow waters can be grasped in color, so that the growth status of vegetation (algae) on coral reefs and shallows due to differences in color can be ascertained. Becomes possible.

  Further, according to the present embodiment, the water bottom observation system 1 includes the laser distance measuring device 4 that can measure the distance to the water bottom in addition to the pair of underwater video cameras 3 and 3 that detect visible light. Due to the depth of the water, the sunlight does not reach and the brightness is insufficient. Therefore, depending on the underwater video cameras 3 and 3 that detect the visible light, it is not possible to accurately create the water bottom surface data, When some of the water bottom surface data obtained by the video cameras 3 and 3 is missing or the water quality is polluted, some of the underwater video cameras 3 and 3 that detect visible light have high accuracy. When data cannot be created and part of the underwater surface data obtained by the underwater video cameras 3 and 3 is missing, when the underwater is photographed by the underwater video cameras 3 and 3 that detect visible light. If the underwater surface data obtained by the underwater video cameras 3 and 3 is partially lost, shading of sun rays or dawn / dusk will occur. At the time, or when the contrast is extremely high, there is a part where the brightness is insufficient and a sufficient exposure cannot be obtained, and part of the bottom surface data obtained by the underwater video cameras 3 and 3 is missing, The laser measurement can be performed even when the underwater surface image obtained by the pair of underwater video cameras 3 and 3 is not successfully combined (image matching processing) and a part of the underwater surface data is missing. It is possible to measure the distance to the water depth by the distance measuring device 4 and to compensate for the loss of the water bottom surface data obtained by the underwater video cameras 3 and 3 that detect visible light. .

  Further, according to the present embodiment, since the pair of underwater video cameras 3, 3, the laser ranging device 4, and the GNSS / gyro device 5 are mounted on the submersible vehicle 2, even in the deep sea bottom region where the water depth is extremely deep. , A pair of video cameras 3, 3 can generate a water bottom image, so that it is possible to visually observe the water bottom area.

  In addition, in the deep sea where the water depth is extremely deep, the sun rays do not reach and the brightness is insufficient, so that it may be difficult to generate a clear water bottom image with the pair of underwater video cameras 3 and 3. In many cases, however, according to the present embodiment, the complementary DSM data is generated by the laser distance measuring device 4, so that it is difficult to generate a clear water bottom image by the pair of underwater video cameras 3, 3. Also in the deep sea area, it becomes possible to obtain the depth of the water bottom, measure the water bottom area, and observe the water bottom as desired.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.

  For example, in the above-described embodiment, a pair of underwater video cameras is provided, but the number of underwater video cameras need only be plural, and is not limited to two.

  Further, in the above embodiment, the laser distance measuring device 4 for measuring the distance to the water bottom is a diffusion member 23 for dividing the laser beam 20 into a number of laser beams 25, preferably manufactured and sold by Advanced Scientific Concepts, Inc. Although a diffusion member used in “3D Flash Lidar” (registered trademark) is used, it is not always necessary to use a laser distance measuring device 4 having this kind of diffusion member 23, and a fiber type Laser distance measuring device, scanning type laser distance measuring device, or the like can also be used.

  Further, in the above embodiment, the sea bottom is observed, but the present invention is not limited to observation of the sea bottom, and can be widely used for observation of a water bottom such as a lake.

DESCRIPTION OF SYMBOLS 1 Underwater observation system 2 Submersible boat 3 Underwater video camera 4 Laser ranging device 5 GNSS / gyro device 7 Video recorder 8 Image processing unit 9 Personal computer 10 Laser data processing unit 11 DSM creation unit 12 Video editor 14 Synchronization signal generator 15 DSM creating unit 16 orthophotograph creating unit 18 orthographic image data processing unit 20 laser beam 21 LED laser light source 22 collimator lens 23 diffusing member 25 laser beam
26 Condensing lens 27 Light receiving sensor 28 Photo sensor 29 CCD sensor 30 RAM
30A first memory area 30B second memory area 31 controller 32 shooting area 33 of a pair of video cameras 33 overlapping shooting area 33A matrix area 35 converting software 40 orthographic image creation software 45 laser beam

Claims (4)

A submersible vehicle that can move underwater,
A plurality of underwater cameras that continuously detect visible light mounted on the submersible,
A laser ranging device that emits a laser beam, receives the laser beam reflected by the sea bottom, and can continuously measure the distance to the sea bottom in synchronization with the plurality of underwater cameras,
An attitude sensor that detects the attitude of the plurality of underwater cameras and the laser ranging device,
A GNSS sensor that detects a shooting position of the plurality of underwater cameras and a measurement position of the laser ranging device;
Synchronously recording photographed image data photographed by the plurality of underwater cameras, posture data of the plurality of underwater cameras detected by the posture sensor, and photographing position data of the plurality of underwater cameras detected by the GNSS sensor. Recording means,
An image processing means for processing a recorded image of the recording means,
The image processing means, for an overlapping range of a plurality of captured images captured by the underwater camera, DSM data to which geographic coordinates are given by image processing based on respective attitude data and captured position data; The DSM data is complemented based on water depth data indicating the distance to the bottom of the water measured by the laser ranging device and attitude data of the laser ranging device detected by the attitude sensor. Complementary DSM data can be created,
The laser ranging device includes a storage unit that stores an emission time and an intensity of the emitted laser beam, a photosensor that detects a detection time of the laser beam reflected by the sea bottom, and a photo sensor that is reflected by the sea bottom. An underwater observation system comprising a light receiving sensor having an area sensor for detecting the intensity of the laser beam.   The underwater observation system according to claim 1, wherein the laser distance measuring device includes a diffusion member that diffuses a laser beam and irradiates the sea bottom with an nxn matrix.   3. The underwater observation system according to claim 1, wherein the plurality of underwater cameras are configured by video cameras that can be controlled by a shutter, and the plurality of video cameras are arranged on the left and right. 4. The underwater observation system according to any one of claims 1 to 3, wherein the attitude sensor and the GNSS sensor are configured by a GNSS / gyro device.

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